Workshop on Methods and Applications of Quantum Computing with Light and Qubits

Tuesday 17 Oct 2023, 08:45 → 19:45 Europe/Prague

B-111 (Břehová 7 -- Faculty of Nuclear Sciences and Physical Engineering)

Aurél Gábris (Czech Technical University in Prague)

The aim of the workshop is to bring together experts from the region focussing on technology and applications for quantum computers, including platforms both with qubits and photons.

The workshop is supported by the Office of Naval Research Global under Agreement No. N62909-23-1-2077.

Arrival and registration

Morning session: Presentations and discussions

Convener: Aurél Gábris (Czech Technical University in Prague)

1 Two-particle Hadamard quantum walk on dynamically percolated line

During a quantum walk on a dynamically percolated graph, some of the graphs' edges can randomly break and reappear again at every time step of the walk. So, dynamical percolations present a possibility to simulate the evolution of systems with imperfections. Although they are generally difficult to study, it is possible to analytically investigate the asymptotic evolution of such systems. Using the formalism introduced in this talk several interesting properties of dynamically percolated systems for single-walker quantum walks have already been revealed. Namely, for some graphs, the possibility of broken edges can cause an improvement in the systems' transport properties. In this talk we present the results for the case of two walkers in one dimension, namely for the special case of dynamically percolated Hadamard walk.

Speaker: Magdalena Parýzková

2 Gaussian Boson Sampling

Speaker: Craig Hamilton

3 What we do in the shadows (in Olomouc)

Speaker: Jan Provazník (Palacký University, Olomouc)

10:25 Coffee break

4 Single-qubit gate teleportation provides a quantum advantage

Speaker: Libor Caha (Technical University of Munich)

5 Iterated non-linear maps of qubit states

Speaker: Igor Jex (FNSPE CTU in Prague)

Afternoon session: Presentations and discussions

Convener: Igor Jex (FNSPE CTU in Prague)

6 Report from NTU hackathon: lessons and experiences

Speakers: Antonín Kříž, Aurél Gábris (Czech Technical University in Prague), Eliška Krátká, Jakub Kučera

7 SQUANDER: a classical framework to train quantum circuits

In this presentation, I will introduce the SQUANDER quantum circuit training framework, which has been jointly developed by the Eötvös Loránd University and the Wigner Research Centre.

Speaker: Péter Rakyta (Eötvös Loránd university)

15:30 Coffee break

8 The simples quantum codes

Speaker: Áron Rozgonyi (Wigner RCP)

9 Nonlinear squeezing as a non-Gaussian resource for quantum technologies

Quantum non-Gaussianity was recently recognized as an important resource for CV quantum information processing, which is necessary for some of the advanced applications, such as quantum computation. The non-Gaussian features of quantum states, often tied to negativity of their Wigner function, are difficult to implement experimentally. The most common experimental sources rely on photon number resolving measurements or interactions with qubit systems, which are both probabilistic approaches. In past we have suggested that one of the elementary non-Gaussian operations, cubic phase gate, can be realized deterministically in a measurement induced fashion if a proper ancillary quantum state is used. This ancillary state possesses a novel kind of non-Gaussianity - the nonlinear squeezing - defined as reduction of variance of a nonlinear combination of quadrature operators. In contrast to vague indicators of non-Gaussianity such as the negativity of Wigner function which is only necessary, the nonlinear squeezing is a sufficient operationally defined quantifier of non-Gaussianity that is directly tied to the performance of the deterministic non-Gaussian circuit. In this talk we present the basic theoretical concept and elementary behavior, several theoretical methods of preparation for quantum states with nonlinear squeezing, and the recent progress in experimental realization.

Speaker: Petr Marek (Palacky University)